Eyes Wide Shut (1999)

Storyline : After his wife, Alice, tells him about her sexual fantasies, William
Harford sets out for a night of sexual adventure. After several less
than successful encounters, he meets an old friend, Nick Nightingale -
now a musician - who tells him of strange sex parties when he he
required to play the piano blindfolded. All the men at the party are
costumed and wear masks while the women are all young and beautiful.
Harford manages to find an appropriate costume and heads out to the
party.